On Heavy Duty Lathes

Comments on the shaper topic lead me to post this on the heavy lathes out there.

Some of this I have said before so bear with me.

In the early 1950's just after the war, The American Tool Works, Lodge and Shipley, Monarch and R.K. LeBlond understood that cutting with carbide tools required a completely different kind of engine lathe.

By 1955, there were:

The Lodge and Shipley PowerTurn

The American Pacemaker Style B,C,D,E and F with number designations (1610-2513).

The Monarch Series 60 and later series 6XX

The LeBlond NE, NI, NF, etc. (not the Regals)

These machines are actually super-lathes.

They are designed for production turning of tough steels in small lot quantities. Manufacturers of printing machinery, paper machines, special process machines, large pumps and large electric motors would be examples of the users of these super-lathes.

A lathe may be assigned shaft work in lots of 20 to 80. Set ups change frequently, work is carefully routed to each lathe according to the size and power available, roughing and finishing may be divided amongst two or more lathes.

Power is the key word. 10HP is the ante, 25 to 30HP on a 16 inch lathe was not all that unusual.

Now, let's imagine a rotor shaft for a big electric motor. It may be six inches in dia. at its largest part and at least four feet long.

This baby would go on a 1610 or a 2013 size of any of the above machines.

At least one of the cuts will be three feet long. Let's get freaky and say the shaft is 4140.

Here is what Monarch thinks you should do. Set the spindle speed so that the work is going at 400-500 SFM. Then take a nice .250 depth of cut for roughing. You can then feed the tool at from .010 IPR to .020 IPR.

Remember our first cut is three feet long. Wanna try that?

You are throwing power at the work. The carbide tool requires high speeds and it also requires very aggressive feeds.

The head stock has to stand up to that all day long, you have from 20 to 80 of these shafts to run.

The feed works has to move the carriage against the resistance of the tool in the cut. All the gears from the spindle to the bed rack have to be able to stand the stress not just once, but all day every day!

These lathes step right along. More power is going through the feed works than most lathes have at the motor!

That is what I call the transmission capacity of a lathe. Can a lathe get power from the motor pulley to the point of the cutting tool?

As if that wasn't enough, along comes the hydraulic tracer. Basically, hit the feed clutch and forget about it. Spindle speeds inch up, feeds get a tad more aggressive. The lathe works longer shifts and spends less time down for change overs.

Super-Lathe saves the day!

Now. some of you are fortunate enough to run or even own one of these babies. Unless you have done the equivalent of manufacturing engineering on the work piece and the set up, don't try the above messing around!

A job like my hypothetical motor shaft would go through the Progress and Planning Dept. then through Tool Engineering and then might be vetted by the Monarch Technician. That technician might even give you a copy of form No. 3613 from 1957. "Speeds and Feeds for Better Turning Results".

These lathes haven't got any sense. They think they are on the floor at General Electric or Worthington Pump. They will go right ahead and do anything that you are fool enough to ask them. If you or anyone else think that you can casually throw 20 HP at a job held in a three jaw chuck, think again.

If you haven't got a tote with forty 4 inch diameter shafts sitting next to your lathe, then you should treat your Monarch or PowerTurn or Pacemaker of NE LeBlond like an ordinary tool room lathe. They are the best there ever was and they do the light and the medium stuff better than any other make or model of lathe.

Just remember, there is a whole 'nother world out there that those lathes are comfortable with and you might not want to go there.

Jim,

I have been following your lathe and shaper topic and it all comes down to respecting any machine no matter what it is and understanding its capabilities and drawbacks.

I am just starting to understand lathe design and this fascinating stuff.

Rick

Amen, again, Jim.

No little South Bend (the Turnado might) would be able to handle that kind of work. I've got a Monarch and a Lodge and Shipley at work. I don't know if either is a Super Lathe as you describe them (both were built in the fifties), but they are heavy duty machines capable of moving ALOT of metal, and they can do the precision work, too.

Andy Pullen

No, Andy, The Turnado won't. Niether will the Ragal or the Cinn. Tray Top or even the mighty Pratt & Whitneys or the Monarch C's and K's.

I am presenting a completely different class of machine tool. The main difference is in the transmission capacity. Any gear head lathe is strong, that is it will develop a large torque. The lathes that I mention will develop that torque at high speeds.

The Pratt & Whitney Model C has a very good apron design, Lodge and shipley copied part of it for their HiTurn production lathes. What the P&W lacks is the transmission capacity through the QC box. The machine is a tool room lathe, the box is for threading, the gears are cast iron. Feeds are restricted to a fine value. You feed at .010 IPR or greater at your peril.

Most gear head lathes out there, even the modern ones are work shop lathes or tool room lathes. They do one-offs or repair jobs. They are made for versatility and easy change over. Running production lots cutting with carbide will wear them right out in a hurry.

May I call it to the group's attention that this topic was written by the one who has love and admiration for the South Bend Lathe. This isn't a criticism of the lighter lathes, rather it is to make the group aware of the true significance of the heavy duty American designed lathe, specifically the models mentioned.

The tracer attachements for these heavy lathes was an indication of what was to come. The Super-Lathe was the original chassis for the tape reading NC lathes. They already had the throughput capacity to keep up with the controls.

The slant bed models, I believe pioneered by the Lodge and Shipley NumeriTurn II, solved problems with tool capacity, clearances and chip dsiposal. Otherwise there wasn't too much wrong with the traditional flat bed design.

CNC and high level programming languages enable longer part programs. The nodern slant bed lathes aren't as heavy as the original machines beacuse they take a greater number of finer cuts.

To this day, you will see flat bed CNC's doing heavy shaft work where solid construction and high transmission capacity are necessary.

The Super-Lathe had about a 20 year heyday. Many shops wouldn't or couldn't find the talent or establish the organization (progress and planning, tool engineering, etc.) to make optimal use of all the speed and power.

The CNC's came on and almost at the same time, a lot of work went off shore or the old line companies in the special machinery field gave up and folded. This was sadly true of the US printing press manufacturers.

I am still current with the concept and processes involved with these Super-Lathes. Now as an Old Man, the best that I can do is to point out that even though these are "modern" machines as far as time is concerned, they are in the somewhat unique position of being significant antique expamles of a particular type and kind of industrial equipment.

The toolroom version of the Monarch 12 x 30, which is also available in any length over 30, by 12" increments ... say 12 x 30, 12 x 42, 12 x 54, 12 x 66, etcetera ... is actually a 14.5 swing, as the true swing is 2.5" larger than the "trade size".

The toolroom models are made to toolroom lathe specifications.

The engine lathe models are made to engine lathe specifications.

Most have helical gears in the headstock and can remove material very fast.

Peter:

Monarch, Lodge and Shipley, LeBlond and American Tool weren't about to make a different machine for tool room work when they had a master's design already in production.

The 12 X 30 Toolroom machine is the same as the 1610 X 78 engine lathe. In most cases the alignments are so close that there wonn't be much different between the engine and tool room models.

These lathes were production made machines. I can't think that a manufacturer would "dirty up" the tolernces just because a lathe was sold as an engine lathe rather than a tool room machine.

If you look at company catalogs, the main difference between the tool room and engine lathe models was the addition of the apron controlled reverse to the lead screw.

All the manufacturers that I mention published bed straightness accuracies for all lathe models as .0005 in. per foot. If the lathe is a Monarch 6xx, it is as accurately aligned as the Model EE.

We had a late 1960's L&S PowerTurn at the Bureau of Standards shop. We didn't run production and the machine was clean and in nice condition. I could shrug my shoulders and rely on the machine. No problem at all holding close tolerances on large diameter work.

If you know how to run a lathe, accurate work is a forgone conclusion.

A lot of production shaft work will have to end up in the grinding shop. You customarily want to leave .015" oversize for cylindrical grinding.

If in a lot of 80 shafts, you are over a bit and under a bit, some guy in the ginding shop will want a word with you. He's got to grind bearing diameters and he doesn't want lathe work dimensions all over the lot.

Make no mistake about it, I don't call these machines Super Lathes lightly.

It would be well to keep things in a historical perspective. "Super Lathes" did not suddenly appear - they naturally evolved from "super lathes" built thirty years earlier for HSS by such as Lodge & Shipley.

To refer to my 24" L&S Selective Head made in 1920 as a "tool room" lathe tends towards the absurd. An example would be its "finest" feed rate of .011 IPR.

We will later this year have photos of headstock internals of this brute to display their relative staying power in over eighty years of working hard day in and day out.

These were the same lathes L&S felt comfortable with in sending out with 10" spindle bores as the first "Oil Country" lathes - about the toughest duty imagineable.

John

thankyou for the insight here. I am ever mindful that my 19 century big swing lathes are not super lathes.

"Monarch, Lodge and Shipley, LeBlond and American Tool weren't about to make a different machine for tool room work when they had a master's design already in production."

The differences were in the minutia, not in the big things.

I didn't mean to imply otherwise.

The toolroom models likely had additional leads in the QC box, and some other small things, but these were indeed every bit as good as their engine lathe counterparts. And vice versa.

During the "golden years" of American lathe manufacturing, there was seldom a poor quality tool being made. Certainly not from Monarch and some of the other "usual suspects".

Now, we're in the "golden showers years" of inferior, off-shore products.

I bought a Lodge and Shipley 25" x 120" lathe for the company I was working for at the time, that came from L & S and was a machine used on their floor. The lathe had a 50 HP motor and has been in use at for the last 20 years in that shop. We used it to bore railroad wheel forgings. The wheels were just under 30" diameter and had a 7" rough bore. we used a 6" diameter boring bar with carbide insert mounted dirct to the cross slide in a custom holder. We took [2] .200 per side passes and [1] .100 pass and held =.001 -.000. Over the years we did several thousand wheels in lots of about 50 at a time, total cycle time per wheel including indicating in +or-.001 was average 20 min per wheel. I don't know if you would call this a high power lathe since it looked like the old round top design but it was a great lathe and sure seemed to have plenty mucle for a machine made in 1953.

"In the early 1950's just after the war, The American Tool Works, Lodge and Shipley, Monarch and R.K. LeBlond understood that cutting with carbide tools required a completely different kind of engine lathe."

Fellas, I'm curious, when carbide tooling first appeared, what was the form, brazed inserts on a steel shank, or ?

If they were brazed, did shops do that themselves or were they purchased as a finished unit?

Was there a particular company that introduced carbide cutting tools?

When did replaceable inserts appear, and what company introduced them?

Paul T.

"Remember our first cut is three feet long. Wanna try that?"

No. I don't even want to sweep up the chips!

Seriously, if I understand you correctly, the "driving force" was the introduction of carbide tooling. This seems like a perfectly reasonable thesis.

There's perhaps a parallel to battleships: Comparing these super-lathes to their predecessors is like comparing Dreadnought-style battleships to Pre-Dreadnoughts. Once these super-lathes came out, any company that wanted to be competitive in heavy machining HAD to buy them. They paid for themselves in machine time saved.

Interesting micro-economics at work here......

John Ruth

Paul T.

The original carbide lathe tools were brazed inserts on steel shanks. Although they had their problems they demonstrated what the new super hard material would do. Carbide tools were not too popular prior to WWII. Stellite was used for the difficult jobs, it is almost as hard and is much less brittle. Stellite can be off hand ground and stone sharpened.

Carbite tools came from the manufacturer already brazed on their shanks. Individual inserts were readily available for those who wanted to braze them on their own shanks and for special tooling.

Brazed shank tools can be resharpened on a so-called carbide grinder. The rough wheel is green colored ( I forget the name of the abrasive) The finishing wheel is a metal bonded diamond wheel.

There were and possibly still are available diamond hones for touching up the edges much like we do with HSS tools.

GE-Carboloy is was the dominant American manufacturer of tungsten carbide. They are now Seco-Carboloy. Someone on the Board mentioned that the Krupp works was the originator of the sintering process used to make the carbides as we know them. Krupp's trade name for it is "Widia".

Obviously, GE used their might and presence in the American market to bring Carboloy here under license from Krupp.

The triangular inserts I have always seen have been GE-Carboloy. I think they were a GE idea.

Carbide tools until very recently have always had rather blunt cutting edges and very few had any kind of positive rank. This causes a cut to consume prodidgeous amounts of power. In addition the reaction to the cut is also huge.

The careful study of the power requirements and the cutting reaction forces led to the development of the super-lathes. Just about any machine tool will cut with carbides, but few but the heaviest and most powerful will allow the carbide tools to be used to their potential advantage.

SB 134:

You are correct. In some cases machining time was cut by 1/4. The insert tools eliminated hand resharpening and most resetting.

The carbide tools not only paved the way for the super lathes, they did so for the lathe tracer and then the NC and then CNC machine which today could not operate without the modern inserts not avaliable a short time ago. GE-Carboloy TNMG's of the older formula will not last on a modern CNC lathe.

The machine tool industry's general motto was "You can't do today's work on yeterday's machines and still be in business tomorrow".

Paul T.

I believe the first carbide cutting tools to come on the market were cemented carbide, brazed to steel shanks. "Carballoy" may have been the first widely available carbide cutting tools in the late 1930's.

Jim K.

You may remember helping me out with some information on acceptance criteria for engine lathes, circa the 1950's. We were getting ready to buy the used/modified heavy duty LeBlond engne lathe from Yancey Machine Tool. What we got was an NK 2510, 25" x 96 heavy dute engine lathe. It had a 50 HP motor on it when we first looked it over. We had no need of that kind of brute power. We went down to a 25 HP motor and have power to spare. When we went out to Yancey Machine Tool for the acceptance tests on the lathe, they had the lathe temporarily levelled and bolted to their shop floor, under power for us. It cut within a few tenths in several feet. We chucked up a hunk of something like 6" diameter 4140 and played with that lathe. I was taking heavier and heavier cuts. Byron Yancey and some other men there kidded me, telling me to "crank in a real hogging cut". I did, and that LeBlond peeled off a cut of One Full Inch (1.000") and didn;t breathe hard. That lathe is rock solid. Levelled up in our plant, we played with a piece of 8" diameter x 8 foot long heavy-wall mechanical steel tubing as a test bar. In about 6 feet, that LeBlond cuts within 0.0002". Properly mounted and levelled in our shop, that LeBlond NK series lathe chjecked out with test bars and cut tighter than what the standards called for a toolroom engine lathe of the same capacity.

By way of comparison, we had a 25" x 96" Soutbend Nordic lathe in our shop. We got rid of it to make way for Marlene, as I came to name the LeBlond. Marlene had been down-powered to only 25 HP with VFD drive. The Southbend/Nordic 25" lathe had a 5 HP motor on it.

About 12 years ago, I bought an older Reed & Prentice engine lathe for the steam locomotive restoration project I am involved in. That lathe is 16" x 50" or thereabouts, known as a "Heavy Toolroom engine Lathe." I believe it has a 10 HP motor on it. I know I had a chunk of 6" diameter nickel alloy steel chucked in it and had no problem taking over 0.600" off in one hogging cut. At the time, the weak link was the lantern style toolpost. We since put an Aloris-type toolpost on, so cured that problem. We routinely turn chunks of old freight car axle to make steam locomotive parts in that old Reed and Prentice. It does not have a problem hogging thru scaly, rough old chunks of freight car axle. The R & P is a beat up old lathe, sitting un-levelled in a box car. It has no problem cutting within 0.002" over a foot or so. That's fine for steam locomotive work.

Jim K. is quite right about the US built lathes of the 1950's. All the major players- LeBlond, Lodge and Shipley, Monarch, American Tool Works, seemed to be building very good lathes that were equal to any amount of rough work. In shopping for our biggest LeBlond (swings 60" over the saddle x 24 feet between centers), I came to learn something of the building of lathes int he USA. Obviously there was a real major glut of engine lathes built for WWII, the "War Production Board" machines. Those were truly great lathes. I ran quite a few of them in various shops and even found them in use overseas. That glut of lathes must've lasted into the 1950's with lathes being kept in government reserves or being sold into the civilian market as surplus.

Along about 1957, the Russians launched Sputnik. That scared the s--t out of the USA. We got busy with a missle building program. The result of that was a glut of even bigger engine lathes, some as big as 96" swing x 30 feet between centers. LeBlond and American Tool Works seem to have been the major players in this league. Many of those big swing/long bed lathes were built as tracer lathes for jobs like missile nose cones and rocket motor nozzles.

Our biggest LeBlond was originally delivered to Aerojet General as a tracer lathe. when Aerojet got done with it, it was sold to a second owner who had it rebuilt and converted to a manual engine lathe. We are the third owner. That LeBlond was built to swing 60" over the corss-slide right from the factory. No "raiser blocks". It was built with a wide bed to get good rigidity. The bed is 54" wide. We never have used that lathe to its full capacity in terms of turning power. We needed the big swing and long bed as well as the rigidity for the jobs we run on it.

Working on the heavier duty lathes or any heavier machine tools is different. You get used to bringing the jobs to and from the lathe with a bridge crane. It is a different kind of work where you have to realize that if your setup isn;t up to the job, stuff is going to get smashed and thrown and the lathe isn't going to breathe hard or stall out.

I am sure that other countries must've built good heavy duty engine lathes or super-duty engine lathes. Perhaps I am prejudiced, and perhaps I am just old enough to be set in my ways. Having run a few lathes in my life and shopped and specified a few more, I tend to believe that the finest, most rugged engine lathes int he world were built in the USA. I've seen Poreba lathes in action and wouldn;t consider buying one new for jobs in our plants. What Poreba considers a heavy duty engine lathe is laughable when you sit it next to an older American Tool Works, L & S, or LeBlond of equivalent capacity and their heavy duty rating. I've seen the stuff coming out of China and wouldn;t consider it for anything in our plants. I've seen Skoda (Czech) lathes as used machines and some German made heavy lathes. While they certainly looked rigid enough for our jobs, they just didn;t "feel right".

FWIW: Watervliet Arsenal, in NY State, used LeBlond gun barrel lathes for years. After a few rebuilds, the arsenal decided to try to replace the LeBlond gun barrel lathes. By that point in time, LeBlond was no longer building new engine lathes. Watervliet bought some German made heavy duty engine lathes. I think they may have been Wohlberg or VDM. In any case, the German made lathes did not hold up in service like the LeBlonds. Watervliet Arsenal approached LeBlond, LTd- the remaining incarnation of LeBlond- and asked about having some new lathes built. They were too late- all patterns had been destroyed. It supports my contention that nothing equals a good older super-duty US built engine lathe. They were the best in the world.

The cutting tools are still under development.

I worked as a lab tech for GTE labs, in the
boston area in the early '80s. The guy I
bowled with in their league there, had an
interesting job.

He tested the cutting tools that were being
prototyped.

I went down to see the setup, the test was
a six inch diameter, 10 foot long piece of steel
that was put in the lathe with an overhead crane.

The test bars had an interesting feature however,
they were sloted along their length with an
approximately half inch wide slot, in four places
around the surface.

This was done to test the toughness of the
inserts under interrupted cuts.

Jim

Jim, wouldn't you care to include some of the Axelsons in your 'Super-Lathe' category, as well?....a 20hp Axelson, with a good operator, will 'get serious' about 'moving the metal' as well as any 20hp Monarch or L & S.

According to some 'folklore', anyway, one of the reasons for the intensive development in turning technology in the '50's was the expiry of some carbide tool patents held by GE, which meant that GE could no longer maintain their monopoly on the Carboloy tooling, for which they'd demanded exorbitant pricing.

I'd offer another thought, if I may, as a necessary part of the definition of a 'Super-Lathe", that being the provision of rapid traverse on the carriage, at least for longitudinal.

Imagine the fatigue level the operator would face in doing that high-production shaft work if he had to crank the carriage back by hand for the start of every cut.....you'd have to have 'Superman' for an operator to get good steady production from your 'Super-Lathe'..... : )

cheers

Carla

Joe:

No Fair! LeBlond NK's and Monarch Series 80's and 90's are not allowed. Most of us don't have bridge cranes hanging over our heads not have plants wired for 25HP, let alone 50.

Natty-Natty-Boo-Boo.

OK, Forrest Addy tells a few good chip shovelling stories, too.

The Germans build a good lathe and they build a good printing press, too.

But.

You have to be German to run them and get long life out of them.

I like the Wohlenberg lathe and having run my share of German machinery, I find no trouble with them.

I also think faily highly of their Heidelberg printing presses.

However -

When you have to run the dog doots out of a machine you have to get an American one.

Our German friends liked the Miller press. (yes, Miller is a nice German name, but the machine was designed and built in Pittsburg, PA.) They liked the machine so much that Miller bought a plant in Johannasburg, Germany and made Millers there.

The miller puts up with the kind of American heavy-handed pounding that gets deadline jobs out the door.

If that wasn't enough, the Swiss have some American and German made Millers also. The press may be rough and ready but they satisfy the finiky Swiss.

We Americans work differently. We are not too impressed with cranky old craftsmen. No matter how sophisticated the machine deign, Americans want a lot of them and they don't want to waste any time making them. We don't care what it is our first question is how many and when do you want them?

Does anyone think these wonderful American made lathes were special, Hell no! Don't stand in the door way, you'd get run over by the mess of machines rolling out.

They make lathes and mills and all kinds of other machinery all over the world now. The only place where that kind of thing is fading away is here.

Only thing is, nobody's manufacturing is strained to the limit the way ours was during WW II. We learned our lessons then. Others have not had the same kind of training. If things get messy, they will get really messy without the stout back bone of American manufacturing to back anyone up.

Carla:

The older Axlesons I have seen are kind of fat. They are big but they don't have a lot of power. I would rank them with the Springfield and the Nebel, the Liehman and the pre PowerTurn Lodge and Shipley's

Now, that goes for the old ones.

In the late 1950's USI-Clearing bought the Axleson Works and intorduced their new model. The main feature was the welded steel lathe bed.

Their advertizing picture in Machinery Magazine in 1958 showed the Clearing-Axleson lathe with an overhead crane hook holding up the tailstock leg of the lathe. The machine was running and cutting a chip.

I have never seen a Clearing-Axleson in real life. Here on the East Coast the Axleson lathe was rare. The only contact that I had with the older Axleson machine was in a Navy shop where I worked for a short time.

Make no mistake about it, the Super-Lathe design would tax the factory where they were made.

All the lathe makers in lower Ohio had excellent gear plants. They all had extensive in house heat treating and superlative grinding shops. All the drive gears in all their head stocks were heat treated and either precision shaved or ground.

All of Monarch's shafts had involute splines, no keys or keyways. Some end gears had to be keyed to their stub shafts. In that case the hole in the gear was broached with the key integral to the body of the gear.

It was common for the Acme lead screws to be ground from the solid, especially the cross feed and compound rest screws.

All of the Super Lathes had hardened and ground cross slide ways on the saddle.

Very few lathe manufacturers had the capital to establish such comprehensive manufacturing facilities and the inspection departments to complement them. The Monarch plant in Sidney must have been able to shame a Swiss. The others were right in there also.

All this time, South Bend was going along nicely, so were many of the others. The point is that it required a Super-Factory to make Super-Lathes and there weren't many of them. We're talking big leagues here.

On the subject or Rapid Traverse, All the manufacturers that I mentioned in my first piece offered it as an option. You had to ask for it. There wasn't much sense in having RT to the carriage on a lathe with less than six foot centers.

Of course Monarch's was the slickest set up. The feed clutch knobs turned into joy sticks. Pushing down engaged the feed as always on a Monarch, but pushing side to side engaged the Rapid in the direction of the push. Monarch had Rapid not only to the carriage but to the cross slide as well.

Excellent post and discussion! Just one thing I want to point out.

The Monarch Series 60 and later series 6XX

Click to expand...

The Series 60 is a pre-super engine lathe, it's spindle speeds are too slow. In 1955 Monarch had the Series 62 (from 1610 through 2516), Series 80 (2516 through 3220) and Series 90 (4025 through 5036). These lathes all had Monarch's DynaShift 36 speed hydrualic shifting headstocks with helical gear final drive. Horse power for the series 62 was 10-20, for the series 80 30-40, and for the series 90, 40 to 50. A series 90 could take 1" depth of cut - now that is one big chip!!!!!!!!!

These machines evolved out of the Model M, N, and NN, and Moanrch's other helical gear lathes. The Series 60 was actual designed for introduction in the early 40's, but WWII delayed intorduction untill 1947. With only 16 speeds ranging from 17-700 rpm, and max HP in the 7.5 to 20 range, the series 60/61 did not have the power nor the speed to but classified along with the Series 62, 612, etc. which replaced it.

John

It would be interesting to trace the step changes that occurred in machine tool design with advances in technology.

Principal among these were the cutting tool materials. Then there was the fortuitous arrival of practical electric motors, which coincided with the discovery that as much power was needed to feed a dull tool as to turn the spindle, once ‘tool steel’ was available.

The main events in tool material seem to be Benjamin Huntsman’s development of crucible steel; Robert Mushet’s highly secretive concoction for alloy tool steels; Taylor and White’s masterly analysis and development of tool alloys and cutting processes; Krupp’s development of sintered tungsten carbide tools.

The story of Krupp’s discovery, as told in L T C Rolt’s book ‘Tools for the Job’ is that Krupp were making sintered tungsten carbide dies for drawing light bulb filaments, and in 1926 one of their machinists decided to see what it could do as a lathe tool. By 1928, Krupp had developed it and exhibited it at the Leipzig Trade Fair. As has been said, it was produced under licence in the US as Carboloy. Wickman had the licence in the UK, and used the names ‘Widia’ and ‘Wimet’.

Each step change demanded major improvements to machine bearing design and precision, not to mention grinding wheel materials.

It strikes me that the phenomenal demand for munitions in WW1 and WW2 must have caused a major shake-up in lathe design. When you look at photos of WW1 lathes producing shells, they look mighty beefy, especially compared with the dainty operators attending to them.

I recently came across a reprint of a book produced by Beyer Peacock of Manchester, recording their WW2 contribution. In more normal times, B-P made locomotives, including the articulated Beyer-Garratts. In WW2 they received massive orders for shells and bombs, and one task was to reduce 180 lb forged steel billets to 80 lb 6 inch shells in no time at all. The only suitable lathes were very complicated, expensive, and German. So they decided to design their own, and have them built by their subsidiary, Garrett’s of Leiston. Conventional lathes would have been useless because of the deluge of chips. Therefore they designed them effectively upside down, with the works above and the chips dropping straight into ‘skips’ below, with buffer hoppers to hold the chips while the skips were emptied. In fact Garrett built a whole production line of special shell machines, all designed to be operated by women, with no heavy lifting.

Garrett’s were very much general engineers, producing anything and everything. I happened to visit the remnants of their factory last week, now the ‘Long Shop Museum’, and found that their range included NC machines and laundromat equipment at the time the firm folded in the 1970s.

The bombs produced by Beyer Peacock were also machined in special lathes. These were double-ended, with the headstock in the middle. The top half of the headstock was hinged at one side, and the bomb shell was held in a massive hollow spindle, enveloped by a gear. Hoists over each lathe lifted the spindle/bomb assembly out after machining, while another one was waiting to be dropped in.